Posts: 43
Threads: 17
Joined: Apr 2010
Just acquired a Philco 42-327, Code 121 and haven't had it long enough to complete the required capacitor replacement, but I have checked all the tubes and found them to test very strong. Someone has already replaced the main electrolytics, but left it at that. The radio fired right up with all the stations in the right place on the dial, but all at very low volume. I quickly tweaked the IF stages just in case someone had mis-tuned them, but they appeared to be right on. I know that the radio is rated at 1 watt output, but this is way below that. Never ran across that particular malady before. Any ideas?
When I do get it working properly, I'm curious if anyone has information on how to change the output stage to provide more volume. I know it would require a bit more work, but I would really like to replace the 50L6 with something with more output.
Posts: 13,776
Threads: 580
Joined: Sep 2005
City: Ferdinand
State, Province, Country: Indiana
Most likely, your culprit is bad paper capacitors. It could be a tube...but poor/leaky old caps are more likely to be the problem.
Quote:When I do get it working properly, I'm curious if anyone has information on how to change the output stage to provide more volume. I know it would require a bit more work, but I would really like to replace the 50L6 with something with more output.
Why would you want to do that? The 50L6 should provide plenty of volume. You can't expect something like a 38-690, but a 50L6 can easily provide lots of audio, enough that you will only have to turn the volume up a little bit when you have it working properly.
I have a 41-226 "Sled" which has a similar 50A5 (loctal) audio output tube. This radio is actually supposed to have a 35A5, but the 50A5 allows the radio to operate comfortably on today's higher line voltage. Anyway, my 41-226 is plenty loud for me; I never have to turn the volume more than 1/2 of the way up - and most of the time, 1/4 of the way up is plenty loud.
--
Ron Ramirez
Ferdinand IN
Posts: 43
Threads: 17
Joined: Apr 2010
You've encouraged me to forget about any modifications. I guess I was a bit discouraged when I saw that the output was only 1 watt. I've already ordered the caps, but they haven't yet arrived. The flat oval speaker was a surprise for me, also. It seems to be in good shape with only one small tear that I have since repaired.
One of the previous owners had disconnected the speaker and sent the output transformer secondary out through an external jack. Going to have to explore that a bit more, to see if the objective was to replace a poorly performing original speaker. The small oval has good voice coil continuity; moves freely without rubbing, and responds to a battery "click" test, but as I mentioned in my posting, yesterday, the output is clean, but extremely weak.
Posts: 7,214
Threads: 266
Joined: Dec 2009
City: Roslyn Pa
If you want to spend the time to troubleshoot it to find a bad cap that you are going to replace anyway. Take a look at all the plate and screen voltage. If they are within spec measure from pin 8 of the 50L6 - to pin 5 of the 50L6 + Should read - 8v or so if it is low than that replace the cap that is hooked to pin 5.
Good Luck
Terry
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
